Ukhathele ukulahleka ekukhethweni kwe-PLC? Landela lezi zimiso ezisebenzayo ezingu-8 ukuze wenze ukukhetha okufanele!
Ukhathele ukulahleka ekukhethweni kwe-PLC? Landela lezi zimiso ezisebenzayo ezingu-8 ukuze wenze ukukhetha okufanele!
Ukhathele ukulahleka ekukhethweni kwe-PLC? Landela lezi zimiso ezisebenzayo ezingu-8 ukuze wenze ukukhetha okufanele!
Ngaphambi kokukhetha i-PLC, isinyathelo sokuqala ukuchaza izidingo zesistimu. Uma lokhu sekucacile, ungakhetha umkhiqizi kanye nemodeli. Kodwa uzenza kanjani lezi zinqumo? Lesi sihloko sinikeza umhlahlandlela onemininingwane wokukusiza ukuthi ukhethe i-PLC evumelana kangcono nezidingo zakho, ehlanganisa abakhiqizi, amamodeli, amaphuzu e-I/O, nemisebenzi yokulawula.
1. Abakhiqizi be-PLC
Lapho kunqunywa umkhiqizi we-PLC, izici ezibalulekile ezifana nezidingo zomsebenzisi, ukujwayelana komklami nemikhiqizo ehlukene, ukuhambisana kwemikhiqizo esekelayo, nokusekelwa kwesevisi yobuchwepheshe kufanele kucatshangelwe. Ngokuvamile, imikhiqizo evela ezinkampanini ezinkulu zamazwe ngamazwe ithembekile. Ezisetshenziswa ezincane, ezizimele noma amasistimu okulawula alula, ama-PLC aseJapane avame ukunikeza inani elingcono. Kuzinhlelo ezinkulu ezinezidingo zokuxhumana eziphezulu nezokuxhumana, ama-PLC wezimboni avela e-Europe nase-U.S. avame ukuba nenzuzo enkulu ngenxa yamakhono awo aphezulu okuxhumana.
Ezimbonini ezikhethekile ezifana ne-metallurgy noma ugwayi, kuyatuseka ukuthi ukhethe amasistimu e-PLC anokusebenza okuqinisekisiwe kanye nerekhodi elithembekile kuleyo mikhakha.
2. Okokufaka/Okuphumayo (I/O) Amaphuzu
Inombolo yamaphoyinti e-I/O iyipharamitha eyisisekelo ye-PLC. Ukuze uthole amaphuzu e-I/O adingekayo, bala inani eliphelele lamaphoyinti e-I/O adingekayo kumpahla yakho yokulawula. Ngokujwayelekile, kufanele ufake i-margin engu-10% kuya ku-20% yokulinganisa. Lapho u-oda, ukulungiswa kufanele futhi kwenziwe ngokusekelwe kuzici zomkhiqizo we-PLC womkhiqizi.
3. Umthamo Wesitoreji
Umthamo wokugcina we-PLC ubhekisele kumayunithi wokugcina wehadiwe ewahlinzekayo. Umthamo wohlelo, isitoreji esisetshenziselwa izinhlelo zokusebenza zabasebenzisi, sincane kunomthamo wesitoreji esiphelele. Njengoba umthamo wohlelo ungaziwa phakathi nesigaba sokuklama (ngaphambi kokuthi kubhalwe uhlelo lomsebenzisi), kulinganiselwa ngokusekelwe kumthamo wesitoreji. Ifomula evamile yokulinganisa yileli: (inombolo yamaphoyinti e-I/O edijithali × 10–15) + (inani lamaphuzu e-analog I/O × 100) = isamba samagama (amabhithi ayi-16 ngegama), anomajini ongeziwe angama-25%.
4. Control Imisebenzi
Lapho ukhetha i-PLC, cabangela izici ezibalulekile ezilandelayo: imisebenzi yokubala, imisebenzi yokulawula, amandla okuxhumana, izici zokuhlela, amathuluzi okuxilonga, nesivinini sokucubungula.
Imisebenzi Yekhompyutha
Ama-PLC ayisisekelo ngokuvamile asekela ukusebenza okunengqondo, isikhathi, nokubala. Ama-PLC ebanga eliphakathi nawo afaka phakathi ukuguqulwa kwedatha nokusebenza kokuqhathanisa. Imisebenzi yekhompyutha ethuthukisiwe efana nokusebenza kwe-algebraic nokudluliswa kwedatha kuvamile kuma-PLC amakhulu. Ama-PLC aphezulu asekela ngisho nokusebenza kwe-PID yokulawula i-analog nezinye izibalo ezithuthukisiwe. Ngokuya ngohlelo lokusebenza, izimo eziningi zidinga kuphela ukusebenza komqondo kanye nesikhathi/ukubala, kuyilapho ukudluliswa kwedatha nokuqhathanisa kungase kudingeke kwezinye.
Control Imisebenzi
Imisebenzi yokulawula ihlanganisa ukulawula kwe-PID, isinxephezelo se-feedforward, ukulawulwa kwesilinganiso, njll. Ama-PLC asetshenziselwa ngokuyinhloko ukulawula ukunengqondo okulandelanayo. Ezimweni eziningi, izilawuli ezilodwa noma ezinamaluphu amaningi ziphatha imisebenzi yokulawula i-analog. Ngemisebenzi yokulawula eyinkimbinkimbi, amamojula ahlakaniphile okufaka/okukhiphayo (isb., amayunithi e-PID noma izinto zokubala ezinesivinini esikhulu) angathuthukisa isivinini sokucubungula futhi alondoloze inkumbulo.
Imisebenzi Yezokuxhumana
Izinhlelo ze-PLC eziphakathi nendawo ezinkulu kufanele zisekele amabhasi amaningi kanye nezinqubo zokuxhumana ezijwayelekile (isb., i-TCP/IP) futhi kufanele zikwazi ukuxhuma kumanethiwekhi okuphatha efekthri uma kudingeka. Izixhumanisi zokuxhumana kufanele zibandakanye izimbobo ze-serial/parallel, i-Ethernet yezimboni, njll. Ukuze kuncishiswe amandla nokuthembeka, amabhasi okuxhumana kufanele ahambisane nezindinganiso zamazwe ngamazwe futhi ahlangabezane nezidingo zebanga.
Imisebenzi yokuhlela
Uhlelo lwe-PLCi-mming ingenziwa ungaxhunyiwe ku-inthanethi (i-CPU eyabiwe phakathi kwe-PLC nomklami) noma ku-inthanethi (ama-CPU ahlukene e-PLC nomklami). Izilimi ezinhlanu zokuhlela ezimisiwe yiShadi Lokusebenza Okulandelanayo (SFC), Umdwebo Wesitebhisi (LD), Umdwebo Webhulokhi Elisebenzayo (FBD), Uhlu Lweziyalezo (IL), kanye Nombhalo Ohleliwe (ST). Ngokufanelekile, i-PLC kufanele futhi isekele izilimi ezengeziwe ezifana no-C noma Eziyisisekelo zezinhlelo zokusebenza ezikhethekile.
Imisebenzi yokuxilonga
Ukuxilongwa kwe-PLC kuhlanganisa kokubili ihadiwe nesofthiwe. Ukuxilongwa kwezingxenyekazi zekhompuyutha kukhomba amaphutha ngokuhlolwa okunengqondo, kuyilapho ukuxilongwa kwesofthiwe kufaka phakathi ukuhlola kwangaphakathi (okuhlobene nokusebenza) nokwangaphandle (okuhlobene nokuxhumana). Amandla okuxilonga aqinile anciphisa isikhathi sokunakekela kanye nezidingo zobuchwepheshe zabaqhubi.
Isivinini sokucubungula
Isivinini sokucubungula se-PLC sithinta ukusebenza kwesikhathi sangempela. Uma ubude besiginali bufushane kunomjikelezo wokuskena we-PLC, isiginali ingase iphuthelwe. Isivinini sokucubungula sincike ezintweni ezifana nobude bohlelo namandla e-CPU. Ama-PLC esimanje aphatha imiyalelo kanambambili kuma-microseconds angu-0.2–0.4, ahlangabezana nezidingo zokulawula isivinini esikhulu. Izikhathi zomjikelezo wokuskena kufanele zibe ngu-≤0.5ms/K kuma-PLC amancane kanye no-≤0.2ms/K kumasistimu amakhulu.
5. Izinhlobo ze-PLC
Ama-PLC ahlukaniswe ngezinhlobo ezihlanganisiwe nezimodular. Ama-PLC ahlanganisiwe anamaphuzu e-I/O alinganiselwe futhi alungisiwe, awenza afanelekele izinhlelo zokulawula ezincane (isb., Siemens S7-200, Mitsubishi FX series). Ama-PLC e-Modular anikezela ngokulungiselelwa okuguquguqukayo kwe-I/O ngamamojula ashintshashintshayo futhi alungele amasistimu amakhulu (isb., Siemens S7-300/S7-400, Mitsubishi Q series).
6. Ukukhetha Imojula
Amamojula weDigital I/O
Amamojula e-Digital I/O ayahluka ekucacisweni (isb., okuphumayo kwe-relay, ukuphuma kwe-transistor) kanye namaphoyinti e-I/O (amaphoyinti angu-8, 16, angu-32). Okuphumayo kwe-relay kuyabiza kodwa kunesikhathi esifushane sokuphila, kuyilapho okuphumayo kwe-thyristor kuyashesha kodwa kubiza kakhulu. Ukukhetha kufanele kuhambisane nezidingo zohlelo lokusebenza.
Amamojula we-Analog I/O
Amamojula okokufaka we-analogi aphatha amasiginali afana ne-4–20mA yamanje noma engu-0–10V. Amamojula okukhiphayo we-analog ngokufanayo ahlinzeka ngamasignali amanje noma kagesi. Amamojula ayahluka ngokubalwa kweziteshi (amashaneli angu-2, 4, 8) futhi kufanele akhethwe ngokusekelwe ezidingweni ezithile.
Amamojula Omsebenzi
Amamojula omsebenzi ahlanganisa ukuxhumana, ukuma, ukuphuma kwe-pulse, ukubala ngesivinini esikhulu, ukulawulwa kwe-PID, namamojula okulawula izinga lokushisa. Lapho ukhetha, cabanga kokubili ihadiwe ne-software ehambisanayo.
7. Imisebenzi Yokungadingeki
Kuzinhlelo zokusebenza ezibucayi, ukuphinda kusetshenziswe kabusha kungasetshenziswa kumayunithi okulawula (isb., ukuphinda kusetshenziswe okungu-1B1 kwe-CPU nokunikezwa kwamandla) kanye nezindawo zokusebenzelana ze-I/O. Ukulungiselelwa okungadingekile kuthuthukisa ukwethembeka kwesistimu.
8. Imithetho Ejwayelekile
Uma uhlobo lwe-PLC nokucaciswa sekuchazwe kabanzi, nquma ukucaciswa okuyisisekelo namapharamitha wengxenye ngayinye ngokusekelwe kuzimfuneko zokulawula. Lapho ukhetha amamojula, beka phambili:
- Ukusebenza kahle komnotho: Ibhalansi yezindleko zokusebenza, ukunwebeka, kanye nokusebenza kalula.
- Ukusebenziseka kalula: Yenza ukuklama kube lula futhi unciphise izici zokulawula zangaphandle.
- Ukumisa: Sebenzisa amamojula afanayo ukuze wenze lula ukuthenga nokugcinwa kahle.
- Ukuhambisana: Qinisekisa ukuthi zonke izingxenye ziyahambelana, zivela kumkhiqizi ofanayo.